Means for cutting oil-well casings and drill pipe



Sept, 6 1927.

H. M. GREENE MEANS FOR CUTTING OIL WELL CASING'S AND DRILL PIPE FiledApril 8 Invezor Patented sept. e, 1921.

UNITED STATES HASKELL M. GREENE, OF WHITTIER, CALIFORNIA.

MEANS FOR CUTTING OIL-WELL CASINGS AND DRILL PIPE.

Application led April 8,

It occasionally happens in drilling an oil well` that due to an accidentor some other unforeseen difficulty the casing or drill pipe or stembecomes wedged or immovably secured in the well,and it is then necessaryto sever the drill stem or casing in order that it may be reclaimed: andit is preferable to sever such casing adjacent the point at which it isheld in order that a maximum length may be recovered.

An object of my invention is to provide a novel explosive torpedo thatwill sever the. drill pipe or casing when exploded.

Another object is to provide a novel torpedo whereby the drill pipe orcasing may be completely severed with a smaller charge of explosive thanhas heretofore been possible.

A further object is to provide a novel torpedo whereby the explosivemixture may be firmly brought into engagement with the walls of thedrill pipe or easing prior to exploding such mixture.

My invention is broadly'new, basicu and pioneer in that I insert withinthe drill'pipe or casing an explosive torpedo having a relatively smalldiameter. then compress and expand the explosive charge so as to bringit into engagement with the walls of the drill pipe or casing. and thendischarge the torpedo while in the expanded position.

Is of the invention are the pro- Feature vision of au efficient` shortlength and small diameter torpedo, which may be readily inserted throughthe hole in the center of the drill pipe connections.r

Further features are that the explosive may be tightly compressed priorto the discharging thereof, and in the provision between the torpedo andthe sand line of a coupling which may bebrokento release the sand lineif desired. i e

I-Ieretofore, explosive charges have been used to sever drill pipes, butsuch 'charges have not been satisfactory because heretofore it wasimpossible to insert a torpedo through the small passages in the drillstem connections that would positively sever the pipe under allconditions. It is well understood that if the explosive charge does notengage the entire periphery of they walls of the drill stem that a holeis liable to be blown out one side or another and the casing or drillstem will not be entirely severed.

1925. Serial No. 21,598.

In this specification it is understood that the term drill stem is acasing.

An object is to provide simple and eiliclent means whereby a drill stemmay be completely severed by an explosive charge set ofl within thedrill stem.

My novel method of cutting drill Stems lcomprises first inserting anexplosive charge into a string of connected drill pipes, thenmalntaining one end of said charge in practlcally fixed relationrelative to the drill stem. then moving the other end of said chargetoward the fixed end thereby contracting and expanding the charge andforc- 1ng it into engagement with the drill stem walls. and thenexploding the charge.

l Other objects, advantages and features of invention, may appear fromthe accompanymg drawing, the subjoined detailed description and theappended claims.

The accompanying drawing illustrates my invention in some of the forms Iat present deem preferable.

Figure 1 is a side elevation of my torpedo in a drill stem, a portion ofwhich is shown 1n section.

Fig. 2 is a view similar to Fig. 1, but showing the torpedo in axiallycontractedy and radially expanded position.

Fig. 3 is an enlarged fragmentally longitudinal axial sectional view ofmy torpedo in a drill stem. y

Fig. 4 is a view similar to Fig. 3, showing the torpedo vaxiallycontracted, and radially expanded against the drill stem.

Fig. 5 is a sectional view on line w", Fig. 3.

Fig. 6 is a sectional view on line me, Fig. 4.

Fig. 7 is a side elevation of my tor edo in position in a well casing afragment o which is shown in section. f

Fig. 8 is a fragmentary detail side elevation of the torpedo point andshowing a slightly modified form of detonator.

Fig. 9 is a fragmentary sectional view of a modified form of torpedopoint and explosive containing tube. i

Fig. 1() is a fragmental detail view showing the wedge means forretaining the slidable collar in fixed relation to the center rod.

The casing a in Figs. 1-4 is the usual hollow drill pipe comprising aplurality of sections 1, 1, etc., which are connected together by theusual connections or collars 2 to form the drill stem. The collars 2 areenv yso

of the usual construction and are provided with a tapered male andfemale threaded section 3 and with the usual passages or openings 4 thatconnect the bores of adjacent sec-tions of the drill pipe.

The collars 2 are provided with inwardly extending shoulders 5, 5. f

My torpedo 6 in normal position is of such a diameter that it willconveniently pass through the openings 4, and may therefore be loweredto any desired depth in the drill stem. The torpedo comprises a point 7,which is formed with a rounded surface or tapered exterior 8 so that itwill more readily pass through the openings 4.

A supporting rod 9 preferably of steel is threaded or otherwise suitablysecured at one end in the point 7, and is provided with a loop 10 at itsother end to receive convenient means for coupling the rod to the usualsand line (not shown). It is desira ble that such connecting means besufficiently weak that it may break before the sand line, yet such meansare strong enough for operative purposes. The connection is made weakerso as to permit the sand line to be released and withdrawn if thetorpedo should become stuck at a point other than where it is desired toex lode' the charge.

A dog carrier or col ar 11 is slidably mounted on the rod 9. Anexpansible, flexible or yieldable explosive containing tube or sheath 12is mounted between the collar 11 and point 7, and comprises a lowermember 13, which has at one end a thick non-ex pansible portion or ring14 that fits a reduced portion 14 on the point 7 and engages a shoulder15 formed by su'ch reduced portion, and also comprises an upper member16 which has at one end a thick non-expansible portion or ring 17 thatlits a reduced portion 11 on the collar 11 and engages a shoulder 18formed thereby on the collar 11.

The other ends of the members 13 .and 16 telescope with each other toform the tube 12, and are sufiiciently thinadjacent the telescoping partto readily expand for engagement with the walls of the drill rod orcasing. The tube 12 may be made of any desirable material, which issufficiently pliable -or expansible, and may be formed in one or morepieces as may be found preferable.

The tube 12 is filled with a suitable eX- plosive, not shown, forpurposes of clearness, but which is well known and is preferably of athick gelatinous consistency. A detonator 19 is positioned -in the tube12 and electric wires 2O extend therefrom through a longitudinal bore orgroove 21 in the collar 1l to a suitable source of electrical energythat is controlled on the surface of the ed in recesses 24, 25,respectively, formed in the upper end of the collar 11, and springs 26,27 engage the dogs 22, 23, respectively, to urge them outwardly. Thesprings 26, 27 fit in recesses 2S, 2i), respectively, in the collar-.11and encircle pins 50 iixed to the dogs 22, 2310 prevent accidentaldisplacement of the springs and dogs.

. A recess 40 is formed in the top of the collar 11 and is adapted toreceive a tapered key 4l that is driven into the recess 40 and againstthe rod 9 to prevent accidental upward movement of the collar 11 on therod 9 and thus also prevents the collar ll from beingl accidentallycaught on projections in the casing and separated from the tube 12 whenthe torpedo is being lowered into a Y casing.

In Fig. 8, I have shown a. modified form ot' exploding the detonator 3()which is mounted on a pin 31 that is secured in the upper end of thereduced portion 14` of point 7, and is adapted to be exploded whenforced against such pin 3l by the collar 11 when the torpedo is axiallycontracted.

In Fig. 9 the explosive container 35 is formed at both ends with a thickend and collar section 36, which is received on the rod 9 and the lowerend section is clamped between a nut 37 above the section 36 and arounded point or washer 38 below the said scction.` A nut 39 holds thewasher in place on the rod. The point 38 may be tapered 1f desired toassist in passing the torpedo through,v the opening 4.

In operation the sand line is secured to the rod .9 and the torpedo 6 islowered into the hollow drill stem a. The diameter of the torpedo issuch that it will readily pass through the openings 4. Vhen the depth isreached at which it is desired to sever the casing or drill stem, thesand line and the torpedo are drawn upwardly until the dogs 22, 23 whichhave been forced outwardly by springs 26, 27 engage the shoulders 5 andprevent'further upward movement of the collar 11. u

Further upward movement of the sand line-draws the rod 9 and point 7upwardlytowards thecollar 11. The middleof the tube12 being thin willreadily bulge outwardly unt-il it comes into engagement with the entireperipherycf the walls of the drill stem, as shown in Figs. 2 and 4.

The explosive in the tube will be tightly compressed in complete contactwith the drill stem and when it is exploded by 'the detonator 19 theforce of the tightly packed explosive will sever the drill stem at thepoint of contact.

The-point 7 and collar 11 are preferably formed of a soft metal so thatthe explosion will shatter them after which the sand line mag be readilywithdrawn.

- s shown in Fig. 7, my' torpedo may be employed to sever a well casing32. The construction of the torpedo is identical to that alreadydescribed, the only difference being that the dogs 22, 23 engage theshoulders formed by the lowerend of a section of casing in the joint 33to prevent upward movement of the collar 11 and as before stated theterm casing includes a drill stem.

.I claim:

1. A torpedo for cutting oil well casing or drill pipecomprising aflexible tube containing an explosive; a rod for supporting said tube,and means to expand said tube against the wall of the casing or pipe onthe upward movement of said rod.

2. Al torpedo for cuttingoil well casing oi' drill pipe comprising arod; a flexible tube containing an explosive; means secuning the lowerend of said tube to said rod;

meansslidably mounting the upper end ot' said tube on said rod; andmeans to expand said tube against thewall of the casing or pipe on theupward movement of said rod.

3. A torpedo for cutting oil well casing or drill pipeV comprising arod; a flexible tube containing an explosive; means securing the lowerend of said tube to said' rod ;f means slidably mounting the upper endof said tube on said rod; means to expand said tube against the Wall ofthe` casing or pipe on the upward movement of said rod; and means todetonate the explosive.

4. A torpedo for cutting oil well casing or drill pipe comprising a rod;a flexible tube containing an explosive; means securing the lower end ofsaid tube to saidrod; means slidably mounting the upper end of said tubeon said rod; means limiting the upward movement of the upper slidablemounting means; and means to draw the rod upwardly and expand said vtubeagainst the walls of said pipe or casing.

5. A torpedo for lcutting oil well casing or drill pipe comprising'a"rod;y a flexible tube containing an explosive; means securing thelower end of said tube to said rod; means sldably mounting the upper endof said tube on said rod; means limiting the upward .movement of theupper slidable mounting means; means to draw the rod up-v wardly andexpand said tube against the walls of said pipe or casing; and means todetonate said explosive..

6. A 'torpedo for cuttingoil well casing" or drill pipe comprising arod, la flexible tube containing an -exp osive; a point securedtol saidrod, a collar slidabl mounted on said rod: means to mount said tube onthe u ward movement of said collar.

7. torpedo forcutting oil well casing or drill pipe comprising'a rod, aexible tube containing an explosive; a point secured to said rod, acollar slidably mounted.on said rod; means to mount said tube on saidcollar and point; means limiting the upward movement of said collar;means to draw said rod upwardly and expand said tube outwardly, andmanually controlled means to detonate said explosive. 8. A torpedo forcutting oil well casing or drill pipe comprising a rod; a flexible tubeu containing an explosive; a point secured to said rod, a collarslidably mounted on said rod; means to mount said tube on said collarand point; dogs pivotally mounted on saidI collar; and means urging saiddogs outwardly to engage an obstruction in the pipe or lcasing and limitthe upward movement of said collar.

9. A torpedo for cutting oil well casing .or drill pipe comprising arod, a flexible tube containing an explosive; a point secured to saidrod, a collar slidably mounted on said rod; said tube `comprising anupper member 35 `a non-expansible ring on one end of sai rod; said tubecomprising an upper member, a non-expansible ring on one end of Saidupper member adapted to encircle said collar, a lower member having anon-expansible ring on one end thereof encircling said point, the outerends of said upperand lower members being thin and telescoping; dogspivotally mounted on said collar and adapted to' engage au obstructionin said pipe or casing; and means to detonate the explosive. y

11. A torpedo forcutting oil well casing and the like, comprising aflexible tube containing an explosive charge; a rod connectled to saidtube, and spring actuated means for holding the torpedo against "upwardmovement during the compression and expension of the tube by the upwardmovement of said rod. l

12. A torpedmfor cutting oil well casing and'the like, comprising aflexible tube containing an explosive charge; a. rod connect- .ed tosaid tube and said rod bein adapted for upward movement to force saitube into engagement with the well casing prior to i lfiring saidexplosive charge.v said collar and point; and meanslimitingf- Intestimon whereof,I I have hereunto set my' hand at os Angels,California, this 2nd day of April, 1925. v

yiiAsKELL M. GREENE.

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